Three-prong loose-leaf binder



Nov. 16, 194& J. MURRAY 2,453,807

THREE PRONG LOOSE-LEAF BINDER I Filed March 15-, 1945 I im-0R Patented Nov. 16, 1948 OFFICE THREE-PRON G LOOSE-LEAF BINDER Joseph A. Murray, Bethesda,

National Blank Book Compan a corporation of Massachusetts Md., assignor to.

Holyoke, Mass,

Application March 15, 1945, Serial No. 582,863 7 2 Claims. (01. 129-47) This invention relates to improvements in the prong type of loose leaf binders. The prong type binder is Well lrnown. It customarily carries an on each side of the back.

number of prong supports extending from each side. The loose sheets can be handled easily for any But if a three prong binder is made the above will not be true. In the opened condition of the binder mechanism, sheets on one side would be hung on one prong only. They would not be held the prongs.

It has been customary to make four prong binders to bind the same sizes of sheets as three ring binders. While the size of these binders size of sheets to be bound, spacing of binding holes in one stock of sheets would serve both the ring and prone: types of binders.

The present improvement in the prong type binder is for the purpose of providing three prongs where before four prongs would be used. To do this in a feasible way a new combination The disclosure is directed to this new combination. It is new and is particularly useful in the stated circumstances.

In the accompanying drawings:

Fig. 1 is a top view with the mechanism in partly opened condition;

Fig. 2 is a top View with the mechanism in closed condition; and

Fig. 3 is an end view of Fig. 2.

In many respects the may be any one of to the invention, however, two prongs should be mounted on one side and one prong on the opposite side. The spacing should correring .book spacing. And in compensate for the ordinarily used in the lock and unlock the binder mechanism with the help of rod 5. When plates l and 2 are turned to locked position, Figs. 2 and 3, a flange 5 cams rod 6 down. It turns on its pivot 1, one in each flange, see Fig. 1, to permit the notches 8 one in each flange, to register. Then spring 4 :snaps rod- 6 into the registering notches of each pair of flanges: 5. Any other suitable locking latch means would serve the combinationso far as the present invention is concerned. a I I The idea of the invention includes. ,the two projecting from plate 2, theplate I, there are I l3 and I4; These members 'areewidely spaced. Onemember I3 is. close to the plane of prong I l. The other one [4, is likewise close to the plane-oi? prong l0. Half way between is prong; bers l3 and M are positioned to support the sheets of a pack from the bottom edges of. the sheets when they are turned over from the right cover to the left cove. The sheets needsno punched holes for such support. Wheln any number of sheets are moved from theside of the and H,

They are kept in this alignment by the underlying members l3 and I4 supporting may be returned in good order from the single prong side to the two prong side. In doing this the sheets are supported on three spaced supports one at the middle hole by the single prong in that hole and one at each of the bottom edges by members l3 and I4 underlying the edges. The consequence is that the sheets are guided back in good order by a three point support until they thread on the two prongs.

The sheets need to be .punched with but three holes. Yet in many respects they are guided as on one side and two on the other. The three hole punching however makes it feasible to use the same stock of sheets in the three prong binder as is used in the three ring binder. There are so many three ring binders in use, as to make it easier toget paper in the retail stocks anywhere, of the three hole punching.

where near as widely used as three ring binders.

An advantage of the prong type binder over the ring binder is the increased capacity or thickness of the pack it can carry for the size of the binder mechanism in the back, see Fig, 3. A full pack of paper is not shown because it is desired to avoid crowding the drawing. If a ring binder were used for the limit of the back portion width the thickness, indicated in the binder of the drawings, the rings would need to be so large as to make a clumsy back portion with respect to its size and space at the back portion. Even then the pack could not be of equal thickness as in a. prong binder. The ring binder is generally preferred until large capacity is wanted, then the prong type binder is wanted. The present invention brings these two types closer together in that the same paper can be used in either type.

Of course prong binders of the prior art are made with many more than four prongs. They are not made so far as I know with less than four prongs. They are characterized by the apparent necessity of an even number of prongs on each side plate of the mechanism. This is the reason, asI know the art, why the four prong binder is the lowest prong numb-er. So the main idea of my invention is a three prong binder, with means in the mechanism to compensate for the lack of a fourth prong, Thus I provide for three as the lowest prong number and get the advantage of using paper punched for the three ring binder. In this broad aspect as well as in the specific aspect of the particular means in the example, I believe the art has been improved by this disclosure.

What I claim is: 1. A prong type binder mechanism comprising pivoted angle plates carrying oppositely disposed prongs overlying substantially the entire back binder portion when in closed prong position, latch means to hold the plates in prong closed condition and release them for prong open condition for threading the paper sheets on and oil? the prongs, such mechanism being characterized byhaving two prongs extending from one plate and a single prong from the other plate to bind plate having the single support sheets from their bottom edges as they are threaded off the two prongs to the single prong side and back again, such supporting members being positioned when in prong closed position one near each of said two prongs and widely spaced from each other with the single prong J arranged between them, such single prong and supporting members being mounted as overhanging projections from one only of said angle plates. 2. A prong type binder mechanism comprising opposite and hinged prong supporting plates, one plate provided with two prongs and the other provided with one prong said prongs when in prong closed position overlying substantially the entire back binder portion, said prongs being spaced to thread into loose leaf sheets with but three perforations in their margin, and means to compensate for the provision of but one prong on one side of the mechanism, said means being characterized by its position in the mechanism to underlie the edges of the sheets as they are carried over from one side to the other and support the sheets from the edges in lieu of any additional prong for such purpose.

JOSEPH A. MURRAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

